Increasing your performance in the gym and preventing many diseases can be as simple as going outside. Here's why.

Go Lie Out in the Sun

If most of the boil-lancing dermatologists had their way, you'd be wearing a hazmat suit every time you ventured out into the sunlight to keep you from getting skin cancer. You'd sound like Darth Vader as you breathed in and out of your mask and scare the bejesus out of the neighbor's kids.

While chronic exposure to the sun and getting burned by the sun are definitely bad ideas, it's also a bad idea to avoid sun exposure altogether. What you need to do is have limited, timed exposure to the sun, without sunscreen, several times a week.

The Problem With Not Enough Sun Exposure

Vitamin D deficiency is a big problem. It's extremely common, and it can cause or exacerbate diseases like multiple sclerosis, cancer, and heart disease. Furthermore, Vitamin D plays a big part in the health of the immune system. Low Vitamin D can also play a role in depression. On the flip side, boosting your Vitamin D levels if they're low has been shown to increase athletic performance.

As such, most Americans get it from taking Vitamin D supplements or Vitamin D fortified dairy products. Your body can manufacture its own, provided it gets enough sun exposure, but as you know the dermatologists have made that practice rank right up there, health-wise, with chain-smoking unfiltered cigarettes while wearing a bag over your head.

The problem, according to leading expert Michael F. Holick, PhD, MD, is that supplemental Vitamin D isn't the same as the Vitamin D produced by exposing your body to sunshine. The Vitamin D produced by sun exposure enters the bloodstream much more slowly and lasts at least twice as long as supplemental Vitamin D.

What About Skin Cancer?

Yes, chronic sun exposure, i.e., tanning, can lead to various skin cancers, most of which are relatively easy to cure. Sunburns, however, can lead to melanoma, which is linked to 10,000 deaths in the US each year.

People who get short-term, occasional sun exposure (without burning) don't have much to worry about. Besides, there's some debate as to the strength of the link between sunlight and melanoma, as plenty of people get melanoma on parts of the body that aren't typically exposed to the sun, like the butt.

The Solution

Here are Dr. Holick's recommendations:

Follow the "no sunburn" rule. He advises people to spend one-half the amount of time in the sun that it would take to develop a mild sunburn.

Get sun exposure between 10 AM and 3 PM when the sun's rays are the strongest.

Keep track of the time. People with dark or darker skin can spend about 30 minutes in the sun, while fair-skinned people should restrict it to about 10 minutes.

Do this three times a week, if possible.

Don't wear sunscreen (which inhibits Vitamin D formation) during this time, except on your face – very little Vitamin D is produced through exposing the face to the sun, plus it leads to wrinkles. Wear sunscreen the rest of the time.